Organizations are generating and accumulating increasingly large amounts of electronic data that needs to be properly retained and promptly accessible when needed. Given the large volume of data involved and the extended retention period for much of this data, it is critical that a storage system have adequate storage capacity. One way of having adequate storage capacity is to use an efficient storage system such as a deduplicating storage system. However, even with a deduplicating system, it is possible to run out of storage space. If storage space is filled up in an unplanned manner, users are not able to store any new data and the system will not be able to fulfill the user's needs.